Basic Line Types

Understanding Line Types

​WHY?

Lines in technical drawings are part of a specialized graphic language that is standardized throughout industry. Each type of line has a very precise symbolic meaning.

​Object Line

Definition: Represents visible edges, outlines, and the main features of an object. It is a solid line without interruptions.

​Hidden Line

Indicates edges or features that are not immediately visible from the current viewpoint. It is represented by a series of short dashes with gaps in between.

Center Line

Represents the centerline of a circle or the axis of symmetry in a symmetrical object. It typically consists of alternating long and short dashes.

​Dimension Line

Indicates the extent or size of an object.

Multiple Choice

What type of line is used to mark the center of a symmetrical object?

• Leader Line

• Hidden Line

• Object Line

• Center Line

Multiple Choice

What type of line is used to communicate information you may not be able to see?

• Leader Line

• Hidden Line

• Object Line

• Center Line

Multiple Choice

What type of line is used to communicate the size of an object or shape?

• Leader Line

• Dimension Line

• Object Line

• Center Line

Multiple Choice

What type of line is used for visible and main features of an object?

• Leader Line

• Dimension Line

• Object Line

• Center Line